Improvement in railway-ties



F. H. WHITMAN.

Railway-Ties.

N0 \57,304,' PatentedvDecJW-SM.

M 2 ya?" l UNITED STATES PATENT OFFICEo FRANCIS H. WHITMAN, OF HARRISON, MAINE.

IMPROVEMENT IN RAILWAY-TIES.

Specification forming part of Letters Patent No. 157,304, dated December 1, 1874 application filed October 19, 1874.

To all lwhom it may concern Be it known that l, FRANCIS H. WHITMAN, of Harrison, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Railway-Sleepers; and I do hereby declare that the following is a full, clear, and exact description thereof, that will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings form-ing a part of this specification, in which is shown a side view of my improved sleeper.

Letters Patent of the United States No. 91,893, dated June 29, 1869, have been granted to E. H. Woodsum and myself for an improvement in railwaysleepers, the improvement consisting in the insertion of rectangular blocks of hard wood into the softer wood ofthe sleeper, whereby the durability of the sleeper was greatly increased, the block of hard wood resisting the pressure and action of the rail, which had before rendered the sleeper useless in a comparatively short space of time..

All desired elasticity was obtained for the sleeper thus constructed by the vblocks inserted acting as an air-cushion; the harder and stronger the piece inserted the less motive power is absorbed, and al longer and better service is obtained in proportion to the solidity, strength, and durability of the block.

lt is found, in practice, that the blocks of hard wood, when exposed to heat while seasoning, or while drying after being wet, are liable to crack upon the surface, thereby impairing to some degree the usefulness and durability of the sleeper.

The purpose of this invention is still further to increase the. durability, first, by securing greater density and specific gravity, and second by preventing the surface cracking. To accomplish this I make use of the following process:

The wood to be treated is passed either in the form of blocks or of planks from which the blocksare cut, between two rollers, weighted sufficiently to give the requisite pressure, each roller being uted or grooved in the line of the axis, or diagonally in relation to the axis.

- By this process the blocks are corrugated upon both the upper and lower surfaces, and at the same time compressed and compacted, giving greater solidity and strength, thus rendering them more capable of resisting pressure, and the changes of climate, and the process of seasoning.

What I claim as my invention, and desire to secure by Letters Patent of the United States, is-

The railway-sleeper, prepared by the insertion of blocks of hard wood, corrugated and compressed as herein described, for the purposes set forth. y

In testimony that I claim the foregoing I have hereunto set my hand this 25th day ot' September, 1874.

A FRANCIS H. WHITMAN.

Witnesses GEC. E. BIRD, ARTHUR 1. BIRD. 

